Automatic telephone-exchange system.



C. L. GOODRUM. AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED M/EYZE), I916- Patanted Feb. 12, 1918.

2 SHEETS-SHEET 1.

C. L. GOODRUM.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED MAY 25. 1916.

1,%6 1 26., Patented Feb. 12, 1918.

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CHARLES I. GOODRUM, F NEW YORK, N. Y ASSIGNOR TO WESTERN.ELEGTRIC eon PANY, INCORPORATED, 01 NEW YORK,

To all whom it may concern:

Be it known that I, CHARLES L. GooDaUM,

New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Automatic Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description. A

This invention relates to circuit arrangements and means for segregating a desired class of calls. 1

In telephone systems it is especially desirable that certain classes of calls, originating in a substation which has limited service, should automatically find an operator who will approve the granting of the limited class of service.

The main feature of this invention is therefore the provision of means for automatically segregating any desired class of calls which require the approval of some authorized person at the exchange before the service is given.

Another feature of this invention is the provision in an automatic telephone system of means for causing the primary stepping ma gnet to take a number of steps which differs from the number of impulses sent by the calling party, and thereafter hunt for an idle trunk line leading to an operator instead of select ng an idle selector switch.

This device will be particularly useful in the case of subscribers who have failed to promptly pay for their telephone service. This class of subscribers'is frequently allowed local service, but is not given service over toll lines. The present invention pro-- vides that calls from such delinquent subscribers will-automatically find an operator who will either grant the service or explain whv the call is not put through.

The drawings considered with the description disclose the preferred. form of the invention for accomplishing this result.

Figure 1 shows the apparatus individual to one subs ribers line. and a first selector including the toll segregating means and the circuit arrangement of the present invention. The mechanism diagrammatically I indicated within the dotted line rectangle at the left of the drawing is individual to a subscribers line, and represents a line switch Specification of Letters Patent. 7 Application flled May as, 1916. Serial No. 99,750.

N. Y., A CORPORATION OF NEW YORK. AUTOMATIC TEIaEPHONE-EXCHANGE SYSTEM.

of the general character disclosed in Patent No. 1,151,543.

Fig. 2 shows [a line finder and a first selector with their associated circuits and a modified form of circuit-closing device for The swi ch employed in the system disclosed in Fig. 1 has but two movable brushes or wipers such as shown .in Patent No. 1,172,585, or in application of O. F. Forsberg, Serial N o. 6302, filed February 5, 1915.

The side switch indicated in the structure may be similar to that shown in Patent No. 815,176, but difiers therefrom inthat in certain instances the wipers are moved upon the energization instead of upon the deenergization of the control magnet. A side switch of this chara ter is disclosed in the application of O. F. Forsberg above referred to.

It is believed that the invention will now be clearly understood by tracing the opera- Patentedheb. as, 1918.

the line and through the substation apparatus, back over the lower side of the line, back contact and right-hand armature of relay 2 and right-hand winding of line relay 1 to ground. Relay 1 pulls up its arma-,

ture and completes an energizing circuit for the plunger operating magnet 3, which may be traced from grounded battery, righthand winding of relay 3. front contact and armature of relay 1 to ground. Magnet 3 is then energized and causes the operation of the plunger or contact operating device by means of which the line spring termie nals 19 and 20 are forced into engagement with the trunk terminals adjacent thereto. According to the well-known operation of a switch of this character, it will be understood that the plunger at the time of its operation is associated with a contact set in which an idle trunk terminated. Upon the closure of the line and trunk contacts, a circuit is com leted from grounded battery, left-hand wmdin of the plunger 0 erating magnet 3, cut-0% relay 2, lower ine spring 20, trunk terminal, relay 5, back contact and armature of relay 6 to ground. Magnet 3 is maintained energized, and relays 2 and 5 attracttheir armatures. Relay 5 at its innermost armature grounds the trunk contact at the master switch, thus causing the idle plunger to move to a posi-' tion before the next idle trunk, in a manner clearly ex lained in Patent No..1,l51.543.

circuits back over the other side of the line,

ri ht-hand armature and front contact of relay 2, switch spring 20,'relay 5, back contact and armature of relay 6 to ground. This interrupts the circuit for the release magnet 6, which would otherwise be established from grounded battery, relay 6, outermost left-hand armature of relay 5, sideswitch wiper 16, back contact and left-hand armature of relay 8, back contacts and armatures of relays 7 and 9 to ground. The energization of stepping relay 7 completes a circuit from grounded battery through relay 8, front contact and armature of relay 7, and back contact and armature of test relay 9 to ground.

The subscriber now works his sending device to interrupt the circuit of relay 7. With the first deenergization of relay 7, primary stepping magnet 10, and the slow release relay 11 are energized in parallel, through a circuit from battery through said relay and magnet, front contact and armature of relay 8, back contact of relay 7, and back contact of relay 9 to ground. The energization of the slow release relay 11 completes a circuit for escape magnet 12 which may be traced from grounded battery, magnet 12, front contact and lefthand armature of relay 11 to ground. Relays 8 and 11 are slow to release, and remain energized during the series of impulses. Each interruption of the line circuit and consequent deenergization of stepping relay 7 causes the primary magnet 10 to move the switch brushes over a group of trunk terminals. The first selector of this system is provided with a commutator and a commutator brush which are utilized to complete a circuit hereinafter described.

At the same time that the line springs engage the trunk terminals through the operation of the contact operating device 4, a third contact spring 21 is forced into engagement with a terminal of the call segregating circuit. This circuit may be traced from grounded battery, relay 23, commutator segment 24, and contact brush 25, which has been stepped around with the selector brushes in response to the actuation of primarymagnet 10, contact sprin 21 to ground 22. It should benoted that i the subscriber is to be given unlimited service, the ground connection at 22 is removed and the call segregatin means will be prevented from operating. elay 23 is energized and attracts its armatures.

Normally at the termination of the impulses from the calling dial, relay attracts its armature, thereby interrupting the previously established circuit of escape magnet 12. In the present circuit arrangement, when relay23 attracts its left-hand armature, the escape magnet 12 is maintained energized by a circuit traced from rounded battery, relay 12, front contact, eft-hand armature of relay 23 to ground. The attraction of the right-hand armature of relay 23 closes a circuit which may be traced from grounded battery, primary \stepping magnet 10, interrupter 26, front ,contact and right-hand armature of relay .23, back contact and grounded right-hand ,armature of relay 11, which relay is now ;deenergized, caused by the opening of its "circuit at relay 7. Primary stepping magnet 10 is energized and under the controlling action of interrupter 26 causes the. se-

lector switch to take an additional step. This additional step of the selector switch removes ground from the commutator segment 24, and thus opens the circuit of the escape magnet. energization, moves the side-switch wipers to second position. Secondary stepping magnet 13 in a well-known manner then actnates the selector brushes to hunt for an idle trunk leading to an operator. This'circuit for the vertical stepping magnet may be traced from grounded battery to the vertical stepping magnet 13, individual interrupter 27 of said magnet, side-switch wiper This ma net, on its de-' 14, front contact and armature of relay 7,

however, the switch brush engages the terminal of an idle trunk which will be connected to ground, relay 9 will pull up, interrupting the circuit of the stepping magnet 13, completing a circuit from grounded batterv through escape magnet 12, front con-' tact and right-hand armature of slow release relay 8, front contact and armature of relay 9 to ground.

The escape magnet is energized and moves the side-switch wipers to position 3 in a manner which is clearly disclosed in applicants application, Serial No. 872,743, filed November 18, 1914.

The substation of the calling party is now connected to the operators position 28,

whereupon a signal,

lay 8 remains energized. This breaks the circuit from battery through release mag net Weil -normal contact 15, and side-switch wiper 16, which would otherwise be completed through the back contact and armature of relay 8,'back contact and armature of relay 7, back contact and armature of relay 0. it the calling subscriber should interrupt his substation circuit while tl1e series of impulses were being sent, stepping relay 7 would fall ofl, causing the deenergination of relay 8 andthe completion of the release circuit just described.

At the time the side switch moves out of the second position, and the stepping relay 7 becomes deenergized, relay 0 is energized, but when the side switch reaches its third position, relay 9 becomes deenergized due to certain changes at the succeeding; selector switch, thus opening up the release circuit Which would otherwise be established from battery through magnet 6, contact 15, wiper 16, back contact and right-hand armature of relay 8, front contact and armature of relay 9. At the termination of the conver sation. relay 9 becomes energized due to circuit changes at the succeeding switch in a manner which will be well understood from the above mentioned application, Serial No. 35,326.

Should the subscriber, after the operation of his line switch, replace his receiver on the hook without operating his sending device, the stepping relay 7 will become deenergized and a circuit will, be completed from grounded battery through the release magnet, the outer left armature and contact of relay 5 and wiper 16 to ground, through the back contacts and armatures of relavs 8, 7 and 9 as before.

The operation of magnet 3 interrupts the circuit of relays 5 and 2 and magnet 3, and if the switch has moved fromvnormal, magnet 6 establishes a holding circuit for itself, which is maintained through the ofi-normal contact 15 until the switch reaches normal position.

The denergization of magnet 3 allows the plunger 4 to be retracted. The retraction of the armatures of relay 2 connects the larized ergized, it attracts its subscribers line to his line relay 1, and the retraction of the armatures of relay 5 removes the busy potential from the trunk contact at the master controller, thus pernnttmg the trunk to again be selected. A modified form of the invention is shown in Fig. 2. In this'system, a line finder is utillzed instead of a line switch, and a porelay is used to complete a circuit for the call se egating means.

Assuming t at the subscriber whose substation apparatus is shown at the left of the drawings, removes his receiver from the hook, a circuit is completed from grounded battery, left-hand winding of line relay 201,

back contact and left-hand armature of out ofi' relay 224, substation apparatus, back contact and right-hand armature of relay 224, right-hand winding of relay 201 to ground. Relay 201 is energized, and attracts its armatures. This completes a circuit from grounded battery, starting magnet 202, back contact and left-hand armature of relay 203, back contact and left-hand armature oi relay 204:, front contact and left-hand armature of relay 201, right-hand winding of this relay to ground. lite-lay 202 is energ1zed and attracts its armatures. At its left armature a circuit is completed from grounded battery, relay 202,1eft-hand armature and front contact of relay 202, back contact and left-hand armature of relay 204, front contact and letthand armature and right-hand winding of relay201 to groun W hen relay 202 is enright-hand armatures. This puts ground on the group test contacts 205, through a circuit which may be traced from ground, back contact and right-hand armature of relay 204-, front contact and outermost right-hand armature of relay 202,

i and the group test contacts 205 of the line finder switches. At the innermost right-hand armature of relay 202 a circuit is completed from ground, back contact and right-hand armature of relay 204, front contact and in; nermost right-hand armature of relay 202, relay 203, and the starter wire 206. If the switch which is normally associated with the group of the calling line is idle, the wiper 207 of the side switch will be placed on the contact associated with the individual interrupting device208 of the rotary stepping magnet 209. fllhis interrupting device may be of any character in which the stepping magnet interrupts its own circuit when it has completed its forward movement. An arrangement of this general character is shown in Patent No. 831,875, and is also disclosed in applicants copending application, Serial No. 872,743.

Assuming that the switch normally allotted to the calling subscribers group is idle, group selection of the switch will take place through the repeated energization and de energization of the stepping magnet 209.

When the group hunting test brush 210 of the switch engages the contact 205, corresponding to the group scriber a circuit will be completed from grounded battery, through the escape magnet 211, and switch wiper 212, brush 210, to contact 205, which has been gpounded by the energization of rela 202. he escap'ement magnet which, in t is case, acts as a test magnet, is energized, and by means of the peculiar structure of the side sw tch, the side-switch wipers 207 212,213, 214. 2471mmediately move to them second position.

If the switch which is normally associated with the calling line group was already5employed, the side-switch wiper 207 wouldfihave been in its third position, and the starter wire 206 would have been continued through I line 215 to the switch of the next group of 80 217, side-switch. wiper 207,

lines, as throu h a line corresponding to 215', as shown at t e lower left-hand of Fig. 2. If that switch should be busy, switch wlper 207 would also be in its third position, and the starter wire would be similarly extended to the switch of the next group, and soon.

The escape magnet 211, having operated, and thecontrolling switch wipers having moved to their second position, a circuit is now completed from battery, through the stepping magnet 216, individual interrupter wire'206, relay 203, innermost right armature and front contact of relay 202, and right-hand armature and back contact of relay 204 to ound. The switch now hunts over the termlnals of the lines in the group in which 'the termi-' nals of the calling subscriber are located. It

may be noted that with the line relay energiz'ed, alternating potential is placed on test terminal 221, from ground, through. the alternating current generator 218, test relay 204, front contact and right-hand armature of relay 201 to the upper side of the line. At this time the controllin switch wiper 214 is in engagement with contact 219. Thus, when the switch brush 220 engages the line terminal 221 of the calling line, a circuit willbe completed from said alternating generator 218, through the test relay 204, line terminal 221, brush 220, wiper 214, contact 219, condenser 222, resistance 223, and polarized relay 225 to ground. Relay 204 will thus receive an energizing impulse of current, and at its right-hand armature, W111 interrupt the circuit for the escape ment magnet 211 and the stepping magnet 216. Magnet 211, in deenergizing, will move the wipers 207, 212, 213, 214, 247 to their third position. Starting wire 206 will now be joined to the starter wire extension 215,

. through the wiper 207.

;Wiper 213 moving into its third position, .will'complete a circuit from-batte 227, cutoff relay 224, lower side of the l ne, wiper 213,1res1stance 223, polarizedrelay 225 to of the calling sub-.

ground. Relay 224 will be energized. thus cutting off the line relay. Relay 204 was deenergized when the wiper 214 moved from contact 219, and relay 202 was prevented from being again energized by the immediate falling off of the armatures of linerelay 201 due to the action of cut-ofi relay 224. The calling subscribers line is now extended through to the side-switch wipers of the selector switch, shown at the right of the drawings in Fig. 2. The calling subscriber may send, by means of his calling dial, the group selecting impulses to the first selector. This "calling dial may be of any desired construction, and operates to cause a series of momentary interruptions of the line circuit. 7 Q g In this modification, a polarized relay is utilized to complete the circuit of the call segregating means. When the subscriber is given unlimited service, the polarized relay is connected to ositive battery. In this case, the relay W111 not put ground on the commutator segment 243, and the call segregating means will not operate. When the subscriber is not given unlimited service, the polarized relay is connected to negative battery. In this instance, when the cut-off relay 224 is energized, a circuit for the polarized relay .225 will be completed from grounded battery 227, cut-off relay 224, lower side of the line, wiper 213, resistance 223, polarized relay 225, to ground. The armature of relay 225 is attracted and puts ground on the commutator segment 243 rom grounded armature 226. A locking circuit is then completed from ounded battery, windings of the polarize relay, wiper 247, which has been moved to its third position with side-switch wipers 207, 212, 213 and 214 and armature 226, to ground.

When the finder side switch moves into the third position, stepping relay 229 is energized through a clrcuit which may be traced from grounded battery, relay 229, wiper 228, wiper 214, brush 220, terminal 221, front contact and armature of relay 224, substation apparatus, left armature and front contact of relay 224, lower side of the line,.wiper 213, resistance 223, polarized relay 225, to ground. When stepping relay 229 is energized, it completes a circuit for ed battery, said relay and stepping magnet second position.

' selector switch in circuit arrangement, the

the relay 232 completes a circuit for the escape magnet 234, from grounded battery magnet 234, front contact and left-han armature of relay 232 to round.

The primary stepping re ay 233 steps the A response to the impulses of the call dial. The first selector of this system, as in the system shown in F i 1, is provided with a commutator which 1s utilized in the call segregating means. Simultaneously with the operation of the selector switch, the brush of the commutator engages the segments of, the commutator.

If the call is of that class which should come to the attention of an operator, commutator brush 242 will stop in engagement with segment 243. This completes a circuit which may be traced from grounded battery, primary stepping magnet 233, individual interrupter 237, wiper 236, back con tact and right-hand armature of relay 232, commutator brush 242, an commutator segment 243, which has been connected to ground through a previously described circuit. Normally at the termination of the impulses from the call dial,escape ma et 234 is deenergized by the interruption 0 its circuit at the armature of relay 232. in this escape magnet is maintained energized through a circuit from grounded battery, magnet 234, commutator crush 242, commutator segment 243, and armature 226, to ground until the additional step has been "iven the primary steppin magnet, througi a circuit from grounds battery, magnet 234, commutator brush 242, commutator segment 243, and armature 226 to ground.

d When the additional step has been given to the primary magnet, the energizing cir cuit for the escape magnet is broken by the commutator brush moving from the segment 243. Escape magnet 234 is thus deenergized and moves the wipers into the The secondary stepping magnet then proceeds to hunt tor an idle trunk. The energizing circuit for this magnet may be traced from grounded battery, magnet 235 individual interrupter 239 wiper 238, ront contact and armature oii relay 229, back contact and armature of relay 231. The terminals of idle trunks are connected with ground and, when the switch brush 24]. engages an idle terminal, a circuit is completed from grounded battery, relay 231, brush 241, and the idle contact to ground. This interrupts, at the armature of relay 231, the energizing circuit for the secondary stepping magnet. immediately upon the en agement oi brush 241 with an idle termina, the operation of mechanism at the successive switch, be deenergized. On

for the release magnet said causes relay 231 to is opened at the armature of this relay 231. The escape magnet is energized and the wipers are moved into the third position.

The substation of the calling party is now connected to the operators position 249 whereupon a signal (not shown), is actuated 1n the well-known manner. The operator then plugs in, and if the service should be granted, connects the calling party with the desired substation at 250. The talking battery for this system is supplied from the operators position 249. At the termination of the conversation, the operator removes the plug from the jack. This energizes the circuit of test relay 231 which completes a circuit for the release 0 the switching mechanism. This circuit may be traced from grounded battery, release magnet 246, ofi-normal contact 245, wiper 244, back contact and left-hand armature of relay 230, front contact and armature of reenergized and completes for itselt a-locking circuit from grounded battery, magnet 246,

off-normal contact 245, front contact and armature of this magnet, to ground. The release circuit for the finder may be traced from grounded battery, release magnet 248, ofi-normai contact P. U. N, back contact and right-hand armature oi relay 203, wiper 244, and to ground through a portion of the circuit previously described. The locking circuit for relay 243 is established from grounded battery, off-normal contact P. 0. N, front contact and armature of relay 248, to ground. The locking circuits for release magnets 246 and 243 are maintained closed until the switch mechanism of the first selector and the finder have returned to normal.

What is claimed is:

l. in a telephone system, an incoming line, two groups sitions, means for normally interconnecting incoming line with any idle outgoing line means operating under predetermined conditions to cause the incoming line to find operators positions before connecting it with one of said groups of idle outgoing lines, and a battery connection for said line for controlling the operation oif said last mentioned means.

2. In r. telephone system, two groups. of incoming lines, two groups of outgoing iines, operators positions, means for normally interconnecting any incoming with any idle outgoing line, means 0 crating under predetermined conditions uring the initiation ofa call to cause the incoming line to find operators positions before connecting it with one of said groups of idle outgoing iines, and a battery connection forcertain of said lines for controlling the operation of said last mentioned means.

3. In a telephone system, two groups of of outgoing lines, operators pollii incoming I: T

are

incoming lines, two groups of outgoing lines, operators positions, switches for normally interconnecting any incoming with may idle outgoing line, a commutator associate with one of said switches, means including said commutator operating under predetermined conditions to cause the incoming line to find incoming and two groups of outgoing ines,

' groups of idle outgoing lines operators positions, switches for normally interconnecting any-incoming with any idle outgoing line, a commutator actuated simultaneously with one of said switches, means including a relay and said commutator cooperating under predetermined conditions to cause the incoming line to find operators positions before connecting it with one of said and a battery connection for certain of said lines for controlling the operation of said last mentioned means.

5. In a telephone system, telephone lines, a switch having movement in two directions for interconnecting said lines, stepping means operated directivelyfor controlling the initial movement of said switch in one direction, and call segregating means includ' ing a circuit associated with said stepping means and switch for automatically continuing the movementof the switch in the same direction as soon as the initial directed movement ceases, said circuit adapted to be closed during the initiation of a call.

6. In a telephone system, telephone lines, a switch having movement in two directions for interconnecting said lines, a selector switch for extending said lines, stepping means for directively controllin the initial movement of said selector switc in one direction, and call segregating means including a circuit adapted to be closed by said first mentioned switch and for automatically continuing the movementof -said selector switch in the same direction when the initial directive movement ceases.

7. In a telephone system, two grou s of incoming and two groups of outgoing ines, a line switch having movement in two directions for interconnectin any incomin with any outgoing line, a se ector switch or extending said lines, means for directively controlling the initial movement of said selector switch, and means controlled b said line switch for automatically continuing the movement of said selector switch in the same direction when the initial directive move; ment ceases.

8. In a telephone system, two grou s of incoming and two groups of outgoing lines, a line switch for lnterconnecting any incoming with any outgoing line, a selector switch for extending said lines, means for directively controlling the operation of said selector switch, and means including a circuit havin a grounded contact located at and contro led by said line switch for automatically operating said selector switch.

9. In a telephone system, two groups of incoming, two groups of outgoing lines, a line switch for interconnecting any incoming with any outgoing line, contacts associated with some of said incoming lines, and actuated by said line switch, a selector switch for extending said lines, means for directivelyoperating said selector switch, a commutator associated with and actuated by said selector switch, and a circuit for automatically operating said selector switch controlled at one of said contacts and said commutator.

10. In a telephone system, two groups of incoming lines, two groups of outgoing lines, a line switch for interconnecting any incoming with any outgoing line, contacts associated with some of said incoming lines and actuated by said line switch, a selector switch for extending said lines, means for directively operating said selector switch, a commutator associated with and actuated by said selector switch, and a circuit including a relay for governing the automatic operation at said selector switch, said circuit being controlled at one point 1) one of said contacts and at another point y said commutator.

11. In a telephone system, two groups of incoming lines, two groups of outgoing lines, a finder switch for interconnecting any incoming with any outgoing line, a selector switch for extending said ines, means for directively controlling said selector switch, a commutator associated with and actuated by said selector switch, and means operative to continue the operation of said selector switch it said commutator has been actuated to a predetermined position.

12. In a telephone system, two groups of incoming lines, two groups of outgoing lines, a tinder switch for interconnecting any incoming with any outgoing line, a selector switch for extending said lines, means for directively controllln said selector switch, a commutator provi ed with a movable brush and conducting segments associated with and actuated by said selector switch, and meansoperative to continue the o eration of said selector switch if said movable brush-has been placed in en agement with apredetermined segmento said commutator. I

13. In a telephone system, an incoming line, oups of outgoing lines, an automatic switc 1, a sending device for controlling saidswitch to extend said mcommg line, and

means whereby when said sending device is operated in accordance withthe designasendin device is actuated in accordance tion of one of said groups of outgoing lines with t e designation of one of said groups said incoming line will be automatically of lines an additional impulse will be transconnected to one of the lines of the other mitted to cause said incoming line to be con- 5 groups. nected to outgoing lines of one of said;. other 14. In a telephone system, an incoming groups. line, groups of outgoing lines, an automatic In witness whereof, I hereunto subscribe switc a sending device for controlling said my name this 24th day of May A. 1)., 1916. switch to extend said incoming line, and 10 means at said switch whereby when said CHARLES L. GOODRUM. 

